Triumph no longer offers a part number for this, and I have seen some aftermarket versions. When I rode through some water, the spray covered my boots and the lower part of the bike. Thinking an extender would help? Suggestions for what works? Can do homemade if I must.
I went for the 'retro' look and got a heavy duty '70s mud flap off eBay for both the front and rear.
The one I have fitted is either a Pyramid Plastics or Power Bronze, can't remember, works fine.
Nick's solution looks as good as several other home made jobs I''ve seen and I'm sure it gets the job done.
there ya go http://www.triumphparts.gbr.cc/index.php/26/435289/